A world champion Thai-style kickboxer was shot to death in the middle ofa busy San Francisco street Friday after he chased down a hit-and-rundriver who had slammed into his parked car minutes earlier.

Alex Gong, 30, was pronounced dead at the scene on Fifth Street nearHarrison Street. Witnesses said he was shot at point-blank range when heconfronted the driver, who apparently waited for a traffic signal to turngreen before opening fire and speeding away.

Gong, who had been working out at the South of Market training gym heruns at 444 Clementina St., was wearing yellow boxing gloves and boxingtrunks when he was killed.

Police had not released a description of the gunman or his vehicleFriday night. But witnesses described him as a Caucasian between 155 and 165 pounds who was driving a green Jeep Cherokee.

The slaying came one day after San Francisco Mayor Willie Brown andother officials announced the start of a campaign to crack down onhit-and-run driving.

The 4:30 p.m. incident began outside Gong's Fairtex gym when his car,also a Jeep Cherokee, was hit by a passing car. Enraged, Gong gave chase on foot, going a block east on Clementina, then a block and a half south on Fifth Street. At that point, Gong confronted the driver, who had been forced to stop as traffic backed up near the Bay Bridge on-ramp.

''The victim put his arm out to stop the driver, the driver pushed himback and then shot him -- point blank," said Marilyn Moore, a witnesswho was riding in a car on Fifth Street.

'I JUST COULDN'T BELIEVE IT' "The victim grabbed himself and fellbackward," she said. "The driver backed up, put the car in drive anddrove off. He turned right on Harrison.

"I just couldn't believe it, I've never seen nothing like that in mylife," Moore said.

Brian Lam, 26, an instructor at Fairtex, said members of the gym saw theinitial fender-bender through an open garage door. Gong, who was insidetraining, took off barefoot after the man, said Lam, who grabbed acamera and followed. "As I was running up, I see Alex arguing with theguy," Lam said. "The light turned green, the guy popped him. Hedefinitely waited for the light to turn green."

Lam said he tried to take a picture of the fleeing Cherokee, but was ina rush to help his mortally wounded friend. "I just yelled for people tohelp," he said.

A motorcycle officer on the way to the Hall of Justice nearby stopped,and he and Lam both attempted to resuscitate Gong.

"Last year, Alex paid for my CPR certification," Lam said. "I was givinghim mouth-to-mouth, the officer was giving him chest compressions."Lam said a single bullet struck Gong just above the heart.

"I thought he was dead maybe 10 seconds after he was shot," Lam said.

S.F. RESIDENT Gong, a resident of San Francisco, was born and raised inNew England, and lived for a time in Central Asia before returning tothe East Coast. He later moved to California and graduated from SanFrancisco State University with a degree in business.

Long interested in judo and tae kwon do, Gong discovered Muay Thai, aform of kickboxing and the national sport of Thailand, in 1994. He oncesaid in an interview that he was drawn to the sport by the fluidmovement and careful balance it requires.

He had a natural affinity for the sport and racked up an impressivearray of championships in the middleweight and welterweight classes. Heappeared regularly on HBO and ESPN and headlined fights at the MGM Grand and the Mirage in Las Vegas. He was a dedicated competitor who trained tirelessly, often waking at dawn to run five miles and perform scores of sit-ups, push-ups and other exercises before going to work.

Gong worked equally hard as a businessman who introduced Muay Thai toCalifornia when in 1996 he opened a San Francisco branch of FairtexCombat Sports Camp -- founded in Bangkok in 1976. It wasn't long before the firm employed 20 instructors and included more than 600 students. It is, according to the company's Web site, the nation's top Muay Thai training facility and the only one recognized by the World Muay Thai Council, which is under the authority of the Thai government.'AN AMAZING GUY' Under Gong's leadership, Fairtex opened anotherfacility in Daly City in 2000.

As Gong's body lay in the middle of Fifth Street, wrapped in a yellowtarp, and police interviewed witnesses, students gathered at Fairtex.They were stunned and spoke with admiration for Gong.

Lam said Gong was a mentor and a leader.

"Alex was an amazing guy," Lam said. "He was the owner, but he was kind of like a big brother. It was a family environment.

"He was a fighter to the end. He was arguing with this guy to get him topull over -- all he had to do was get his plate, but he had to get intoit with him," Lam said.

Man sought in killing of S.F. kickboxing champion shoots selfBy Emily Fancher and Amy Yarbrough, STAFF WRITERSSOUTH SAN FRANCISCO -- A man who had barricaded himself in a motel room since late Sunday night shot and killed himself just after noon Monday, police said. Officers had been at the Travelodge motel, 326 South Airport Blvd., since about 9 p.m., after receiving a tip that a man wanted in a fatal shooting last week in San Francisco was staying there, said South San Francisco Police Lt. Roy Varney.

Negotiators contacted the man, who had refused to come out of his motel room, but he stopped communicating with them around 6:30 a.m.

At about 12:23 p.m. police heard a single gunshot, and found the man dead beneath a mattress in a neighboring room with a gunshot wound to the head, police said. It appears he had broken through a wall to the adjoining room.

Authorities would not identify the man, but said he was a parolee, and Varney said he was a suspect in the Friday shooting death of Thai-style kickboxer Alex Gong.

San Francisco police seemed more hesitant about making that connection Monday afternoon.

"We do not know if this person was the actual killer," said SFPD spokesman Dewayne Tully. "But what we do know is that there was some evidence left in an abandoned car that indicates there may be a connection between this man and the killing."

San Mateo County coroner's officials did not release the identity of the dead man, but said he was 24 years old. The County coroner said Monday he had not yet reached family members to notify them of the death. Coroner's investigator Robert Bergstrom said Monday night the man apparently died of a self-inflicted wound.

An autopsy is scheduled for today.

Gong, 30, was shot and killed after he chased down and confronted a driver who had crashed into his SUV parked near his San Francisco kickboxing gym.

The suspect's Jeep Cherokee, which was later determined to be stolen from Pacifica last month, was found abandoned at a Chevron station in Millbrae late Friday night.

Sgt. Mike Brosnan said a team of three negotiators who spoke with the man several times throughout the night by phone described his demeanor as "calm and quiet."

Dozens of police officers and SWAT team members surrounded the motel and police evacuated a wing of the motel -- between 12 and 15 rooms -- early this morning.

Around 6:30 a.m., a woman came out of the suspect's room and was questioned by police. Brosnan said she was not a suspect in the case and described the two as having a "friendly relationship."

After hours of failed negotiations, members of the San Mateo County SWAT team broke the window of the room. Later, they threw in a "flash-bang" grenade, which makes noise and emits smoke, to get the man's attention and to "get him talking again," Brosnan said.

Travelodge was planning to have catered food brought in for the displaced guests, some of whom milled about the motel grounds, waiting for word on when they could get back into their rooms.

About 100 to 200 feet away from police, kids and families splashed about in the motel's pool.

Robert Rozar, who was staying at the motel, said he and a co-worker were awakened at 1:30 a.m. and told to leave their room.

"The front desk called us and said, 'There's a police emergency and you need to get out now,'" he said.

Rozar, from San Diego, said he was in the area on a construction job on a local golf course but couldn't get to work because he couldn't get into his room to get his safety gear and equipment.

"We can't go to work because we don't have our stuff," he said. "It's costing us quite a lot of money."

Roman Fan, a Berkeley resident who knew Gong, said he drove to South San Francisco after hearing about the standoff, "to see if it's really him (Gong's shooter) and to get closure."

Gong, who headlined kickboxing fights in Las Vegas and appeared on ESPN, had been working out at Fairtex Muay Thai Camp, a martial arts studio he owned, before he was gunned down.

Police say he was still wearing boxing gloves and trunks when he ran two and a half blocks to catch up with the Jeep's driver, who waited for a traffic signal to turn green before opening fire and speeding away.

Fan, a fellow kickboxer, said Gong had a great heart and was known to help out homeless people near his gym, giving them food and blankets. He called him "a superstar."